Abstract:

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The crack problem for a functionally graded orthotropic coating-substrate structure under
an in-plane load is studied. The orthotropic coating is assumed to contain a crack perpendicular to the
interface. Integral transform method is used to obtain singular integral equation. Stress intensity
factors (SIFs) are evaluated. The influences of orthotropic material constants and the geometry
parameters on SIFs are analyzed.

Abstract: In this paper we study the behaviour of a Mode I crack in a pre-stressed wood composite material. A mathematical model is associated to the mechanical problem. Starting from the boundary, constitutive and far field conditions we obtain the representation of the incremental displacement, stress and strain fields using two complex potentials. Using numerical analysis we determine the critical value, which causes crack propagation and the direction of crack propagation in a particular case of a Pine wood composite.

Abstract: The problem of orthotropic bi-materials semi-infinite interfacial crack was studied, by constructing new stress functions and using composite complex functions methods of material fracture on plane. It overcame oscillation singularity of stress and existing theoretical solution. When secular equations’ discriminations are and , the theoretical solutions to the stress fields and the displacements fields of semi-infinite interface crack between two dissimilar orthotropic composite materials near the crack tip are obtained.

Abstract: The problem of orthotropic composite materials semi-infinite interfacial crack was studied, by constructing new stress functions and employing the method of composite material complex. In the case that the secular equations’ discriminates the and theoretical solutions to the stress fields and the displacement fields near semi-infinite interface crack tip without oscillation and inter-embedding between the interfaces of the crack are obtained, a comparison with finite element example was done to verify the correction of theoretical solution.

Abstract: The orthotropic bi-material plane interface end of a flat lap is studied by constructing new stress functions and using the composite complex function method of material fracture. When the characteristic equations’ discriminates and , the theoretical formulas of stress fields, displacement fields and the stress intensity factor around the flat lap interface end are derived, indicating that there is no oscillatory singularity. There are multiple stress singularities of the orthotropic bi-material plane flat lap interface end.

Abstract: The orthotropic bi-material plane interface end of a flat lap is studied by constructing new stress functions and using the composite complex function method of material fracture. When the characteristic equations’ discriminates and, the theoretical formulas of stress fields, displacement fields and the stress intensity factor around the flat lap interface end are derived, indicating that there is no oscillatory singularity. There are multiple stress singularities of the orthotropic bi-material plane flat lap interface end.